[DOCS] Removes the default size definition of thread pool types (#49442)

Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
This commit is contained in:
István Zoltán Szabó 2019-11-22 11:15:35 +01:00
parent d444c334d7
commit 35cc0e0948
1 changed files with 20 additions and 19 deletions

View File

@ -10,7 +10,7 @@ of discarded.
There are several thread pools, but the important ones include: There are several thread pools, but the important ones include:
`generic`:: `generic`::
For generic operations (e.g., background node discovery). For generic operations (for example, background node discovery).
Thread pool type is `scaling`. Thread pool type is `scaling`.
`search`:: `search`::
@ -20,8 +20,9 @@ There are several thread pools, but the important ones include:
`1000`. `1000`.
[[search-throttled]]`search_throttled`:: [[search-throttled]]`search_throttled`::
For count/search/suggest/get operations on `search_throttled indices`. Thread pool type is For count/search/suggest/get operations on `search_throttled indices`.
`fixed_auto_queue_size` with a size of `1`, and initial queue_size of `100`. Thread pool type is `fixed_auto_queue_size` with a size of `1`, and initial
queue_size of `100`.
`get`:: `get`::
For get operations. Thread pool type is `fixed` For get operations. Thread pool type is `fixed`
@ -29,7 +30,8 @@ There are several thread pools, but the important ones include:
queue_size of `1000`. queue_size of `1000`.
`analyze`:: `analyze`::
For analyze requests. Thread pool type is `fixed` with a size of 1, queue size of 16. For analyze requests. Thread pool type is `fixed` with a size of `1`, queue
size of `16`.
`write`:: `write`::
For single-document index/delete/update and bulk requests. Thread pool type For single-document index/delete/update and bulk requests. Thread pool type
@ -49,8 +51,9 @@ There are several thread pools, but the important ones include:
keep-alive of `5m` and a max of `min(10, (# of available processors)/2)`. keep-alive of `5m` and a max of `min(10, (# of available processors)/2)`.
`listener`:: `listener`::
Mainly for java client executing of action when listener threaded is set to true. Mainly for java client executing of action when listener threaded is set to
Thread pool type is `scaling` with a default max of `min(10, (# of available processors)/2)`. `true`. Thread pool type is `scaling` with a default max of
`min(10, (# of available processors)/2)`.
`fetch_shard_started`:: `fetch_shard_started`::
For listing shard states. For listing shard states.
@ -101,8 +104,7 @@ The `fixed` thread pool holds a fixed size of threads to handle the
requests with a queue (optionally bounded) for pending requests that requests with a queue (optionally bounded) for pending requests that
have no threads to service them. have no threads to service them.
The `size` parameter controls the number of threads, and defaults to the The `size` parameter controls the number of threads.
number of cores times 5.
The `queue_size` allows to control the size of the queue of pending The `queue_size` allows to control the size of the queue of pending
requests that have no threads to execute them. By default, it is set to requests that have no threads to execute them. By default, it is set to
@ -131,8 +133,7 @@ https://en.wikipedia.org/wiki/Little%27s_law[Little's Law]. These calculations
will potentially adjust the `queue_size` up or down by 50 every time will potentially adjust the `queue_size` up or down by 50 every time
`auto_queue_frame_size` operations have been completed. `auto_queue_frame_size` operations have been completed.
The `size` parameter controls the number of threads, and defaults to the The `size` parameter controls the number of threads.
number of cores times 5.
The `queue_size` allows to control the initial size of the queue of pending The `queue_size` allows to control the initial size of the queue of pending
requests that have no threads to execute them. requests that have no threads to execute them.
@ -187,6 +188,7 @@ thread_pool:
[float] [float]
[[processors]] [[processors]]
=== Processors setting === Processors setting
The number of processors is automatically detected, and the thread pool The number of processors is automatically detected, and the thread pool
settings are automatically set based on it. In some cases it can be settings are automatically set based on it. In some cases it can be
useful to override the number of detected processors. This can be done useful to override the number of detected processors. This can be done
@ -200,15 +202,14 @@ processors: 2
There are a few use-cases for explicitly overriding the `processors` There are a few use-cases for explicitly overriding the `processors`
setting: setting:
. If you are running multiple instances of Elasticsearch on the same . If you are running multiple instances of {es} on the same host but want {es}
host but want Elasticsearch to size its thread pools as if it only has a to size its thread pools as if it only has a fraction of the CPU, you should
fraction of the CPU, you should override the `processors` setting to the override the `processors` setting to the desired fraction, for example, if
desired fraction (e.g., if you're running two instances of Elasticsearch you're running two instances of {es} on a 16-core machine, set `processors` to 8.
on a 16-core machine, set `processors` to 8). Note that this is an Note that this is an expert-level use case and there's a lot more involved
expert-level use-case and there's a lot more involved than just setting than just setting the `processors` setting as there are other considerations
the `processors` setting as there are other considerations like changing like changing the number of garbage collector threads, pinning processes to
the number of garbage collector threads, pinning processes to cores, cores, and so on.
etc.
. Sometimes the number of processors is wrongly detected and in such . Sometimes the number of processors is wrongly detected and in such
cases explicitly setting the `processors` setting will workaround such cases explicitly setting the `processors` setting will workaround such
issues. issues.